The present invention relates to a multiple orifice spray tip for airless spraying that can be used with high pressure liquid spray systems such as paint sprayers.
High pressure airless paint spraying equipment generally consists of a pump to develop fluid pressure, a hose, a gun or shut off device and a spray orifice, or tip, held to the front of the gun with a retainer. Fluid is delivered to the gun via the hose and exits the system through the spray tip. A spray tip for airless paint spraying consists of a small orifice through which the paint is forced at high pressure. The shape and size of the orifice opening determines the shape of the spray pattern and the amount of paint being applied.
The small size of the spray tip orifice opening often results in plugging of the opening. A common remedy for this condition is to reverse the direction of the material flow through the orifice. This can be achieved by rotating the spray tip 180 degrees within the tip retainer, forcing material through the orifice in the opposite direction to dislodge the plug. Once the foreign matter is purged from the orifice, the spray tip is rotated back 180 degrees to resume spraying. This method of xe2x80x9creversiblexe2x80x9d cleaning or xe2x80x9creversible spray tipsxe2x80x9d is disclosed in U.S. Pat. No. 949,489.
Commonly sprayers are operated from ladders, scaffolding, man-lifts. The structure being painted may be a tower, water tank, bridge, ship, ceiling or other difficult to access surface. The ability to change spray tips in the simplest manner possible is desirable. This includes minimal disassembly of parts that can drop and be lost, rendering the sprayer inoperable. The need for tools for spray tip interchange increases the number of items that must be on hand in remote locations as well as increases the complexity of the task of changing spray tips. Furthermore, removing the spray tip is required when cleaning the system, replacing worn tips and selecting a tip with different spraying characteristics. Spray tip interchangeability is complicated by the need to produce a seal between the nozzle and the spray gun that will not leak under high pressure.
The abrasive nature of paint as well as the high pressures required to operate an airless spraying system leads to rapid wear of the spray tip orifice. Significant wear can be seen in as little as 8 gallons of paint. Wom spray tip orifices increase the volume of paint allowed to flow through them. Additionally, worn spray tip orifices reduce the size of the spray pattern produced. The combination of a reduced spray pattern and a higher flow of material cause a number of problems for the operator including; poor finish quality, inconsistent coverage, runs and sags. Material and time is wasted as more paint is applied to a smaller surface area. For this reason it is practical to replace worn tips frequently. Furthermore paint sprayers have a maximum orifice size they can support based on the output of the paint pump. If a spray orifice wears to a size larger than that which the paint pump can support, spraying pressure decreases and the coating no longer atomizes resulting in poor surface finish quality.
There is a continuing need for reversible spray tip members having multiple orifices housed within a single spray tip body.
This invention provides a faster and simpler way of exchanging a worn spray orifice for a new one. This invention requires no modifications or additional parts to be used on the majority of airless spray systems currently available. For these reasons this invention provides multiple spray orifices of the same size and oriented in the same orientation within one spray tip. The additional orifices are provided as replacements to compensate for the effects of a worn orifice and not as orifices which produce different spray characteristics. Given the ability of the operator to vary spray pattern size and coverage thickness by varying speed and distance to surface, the ability to access a fresh, unworn orifice is more valuable than accessing an orifice of a different size.
It is the purpose of this invention to provide a spray tip that is quickly interchangeable, has multiple orifices and is rotatably cleanable. Furthermore, the invention combines these three features while operating within a standard unmodified tip retainer. Such a retainer is the most common type available and already in place on the majority of spray guns. The size of the spray orifices is critical for allowing correct placement of the spray orifices within the cylindrical turret. The spray orifices must be sized so as to allow for multiple orifices to fit on a cylinder of the size necessary to fit within commonly available tip retainers. Furthermore the spray orifices must be spaced along the cylindrical turret so as to cover the inactive spray orifice to protect it from contamination by overspray or paint build up.
Specifically, the present invention provides, in a spray gun of an airless spray system comprising a housing, a spray guard, a transverse passage and an orthogonal bore connected to the transverse passage, a removable, rotatable cylindrical turret member having a handle and at least one orifice member mounted in at least one transverse bore, the turret member being adapted for insertion into the orthogonal bore of the spray gun housing in a position wherein at least one of the orifice members of the turret member is aligned with the transverse passage, the turret member further comprising at least one removable spacer.
The present invention also provides, in a spray gun comprising a housing, a spray guard, a transverse passage and an orthogonal bore connected to the transverse passage, a removable, rotatable cylindrical turret member having a handle and at least one orifice member mounted in at least one transverse bore, the turret member being adapted for insertion into the orthogonal bore of the spray gun housing in a position wherein at least one of the orifice members formed in the at least one transverse bore of the turret member is aligned with the transverse passage of the housing, the turret member further comprising at least one removable tab positioned to interact with the housing to limit the rotational movement of the turret when inserted into the orthogonal bore of the spray gun housing.
The present invention also provides a turret member assembly for use with a spray gun of an airless spraying system, the spray gun comprising a spray gun housing, the spray gun housing having a longitudinal passage connected to an adjacent orthogonal bore, the orthogonal bore being adapted for the insertion of the turret member, the turret member being cylindrical and having at least two transverse passages formed therein, each passage having an orifice spray tip member disposed therein, the turret member further comprising a handle and at least one removable spacer.
The present invention also provides a turret member assembly for use with a spray gun of an airless spraying system, the spray gun comprising a spray gun housing, the spray gun housing having a longitudinal passage connected to an adjacent orthogonal bore, the orthogonal bore being adapted for the insertion of the turret member, the turret member being cylindrical and having at least two transverse passages formed therein, each passage having an orifice spray tip member disposed therein, the turret member further comprising a handle and at least one removable spacer; the housing further comprising at least two parallel channels formed therein, each channel being adapted to interact with one of the at least one removable spacers to define and restrict the position and rotational movement of the turret when inserted into the orthogonal bore.
The present invention also provides a turret member assembly for use with a spray gun of an airless spraying system, the spray gun comprising a spray gun housing, the spray gun housing having a longitudinal passage connected to an adjacent orthogonal bore, the orthogonal bore being adapted for the insertion of the turret member, the turret member being cylindrical and having at least two transverse passages formed therein, each passage having an orifice spray tip member disposed therein, the turret member further comprising a handle and a tab; the housing further comprising at least two parallel channels formed therein, each channel being adapted to interact with the tab to define and restrict the position and rotational movement of the turret when inserted into the orthogonal bore.